Florida’s iconic manatee population is highly likely to endure for the next 100 years, so long as wildlife managers continue to protect the marine mammals and their habitat, a new study by the US Geological Survey and the Florida Fish and Wildlife Research Institute has found.

The new study follows the U.S. Fish and Wildlife Service’s downlisting of the manatees’ status to threatened from endangered on March 30.

The report produced by a team of veteran manatee scientists estimated there is less than a one-half of one percent chance that either Florida’s Atlantic or its Gulf of Mexico manatee population could fall to as few as 500 adults – the level that could imperil Florida manatees’ long-term survival.

“Still, new threats could emerge, or existing threats could interact in unexpected ways,” Runge said. “Managers need to remain vigilant to keep manatee populations viable over the long haul.”

Florida’s manatee population is likely to gradually double over the next 50 years and then level off, the research team concluded. Over time, environmental and habitat changes will probably cause manatees to become less abundant in South Florida and more numerous in North Florida, but the population as a whole will remain high.

The biggest threats will continue to be fatal collisions with watercraft and the loss of warm-water habitats that provide them with refuge during the winter. Water colder than about 70 degrees can kill manatees.

The new analysis projects that mortality due to red tide will become an equally significant threat, if red tides are more frequent and more intense in coming decades.

The Florida manatee is a subspecies of the West Indian manatee. In the mid-1970s only about 1,000 manatees survived in Florida. But over the last 40 years, boat speed regulations, habitat protection and other measures have helped the population rebound. This year’s count found 6,620 manatees in Florida waters.

“Manatee populations will continue to face threats,” Runge said. “But if these threats continue to be managed effectively, manatees will be an integral and iconic part of Florida’s coastal ecosystems through the coming century.”